JPWO2019102724A1 - Communication equipment, programs and communication methods - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication device capable of performing wireless communication more efficiently. SOLUTION: A first communication unit that uses a first channel to exchange frames with another communication device based on the IEEE 802.11 standard, and a second communication unit having a frequency band different from that of the first channel. A communication device including a second communication unit that communicates a data frame with the other communication device using a channel, and a control unit that controls communication of the data frame based on the result of the frame exchange. [Selection diagram] Fig. 2

Description

The present disclosure relates to communication devices, programs and communication methods.

In the IEEE802.11 standard, access control of a large number of terminals is performed by CSMA / CA (Carrier Sense Multiple Access with Collision Availability). Access control is performed by RTS / CTS frame exchange or the like, and in the case of access control, a time required for RTS / CTS frame exchange, a waiting time before data transmission, and the like occur. The time required for access control may occupy most of the communication time, which can be a large overhead in communication. Further, since the frame used for access control is transmitted in a narrower band than the data frame, the frequency utilization efficiency is lowered by the transmission of the control frame. Therefore, a technique has been developed that uses a channel different from the channel for transmitting data.

For example, Patent Document 1 discloses a method of using a channel for data transmission and a channel different from that for data transmission as a tone channel. In the method of Patent Document 1, the tone channel confirms the usage status of the data channel by transmitting and receiving signals for confirming the response between the devices. Each terminal can determine whether a data channel is available by carrier-sensing this tone channel.

Japanese Unexamined Patent Publication No. 2006-246142

However, since access control such as acquisition of the data transmission right described in Patent Document 1 is performed by normal back-off control in the data channel and RTS / CTS frame exchange, overhead generated during access control. Has not been reduced.

Therefore, the present disclosure has been made in view of the above, and provides new and improved communication devices, programs, and communication methods capable of performing wireless communication more efficiently.

According to the present disclosure, the first communication unit that uses the first channel to exchange frames with other communication devices based on the IEEE802.11 standard and the first channel have a frequency band different from that of the first channel. A communication including a second communication unit that communicates a data frame with the other communication device using the two channels, and a control unit that controls the communication of the data frame based on the result of the frame exchange. Equipment is provided.

Further, according to the present disclosure, the first communication unit, which exchanges frames of a computer with another communication device based on the standard of IEEE802.11 by using the first channel, is different from the first channel. A second communication unit that communicates a data frame with the other communication device using a second channel that is a frequency band, and a control unit that controls communication of the data frame based on the result of the frame exchange. A program is provided to function as.

Further, according to the present disclosure, the first channel is used to exchange frames with other communication devices based on the standard of IEEE802.11, and the second channel is a frequency band different from that of the first channel. A communication method performed by a processor, comprising communicating a data frame with the other communication device using a channel and controlling the communication of the data frame based on the result of the frame exchange. Is provided.

As described above, according to the present disclosure, wireless communication can be performed more efficiently.

It should be noted that the above effects are not necessarily limited, and together with or in place of the above effects, any of the effects shown herein, or any other effect that can be grasped from this specification. May be played.

It is a figure which shows the structure of the communication system which concerns on one Embodiment of this disclosure. It is a block diagram which shows the functional structure example of the communication apparatus which concerns on this embodiment. It is a block diagram which shows the functional structure example of the control part which concerns on the same embodiment. It is a figure which shows the example of the format of the RTS frame which concerns on the same embodiment. It is a figure which shows the example of the format of the CTS frame which concerns on the same embodiment. It is a sequence diagram which shows the operation example of the communication system which concerns on this embodiment. It is a flowchart which shows the operation example of the communication device of the transmission side which concerns on this embodiment. It is a flowchart which shows the operation example of the communication device on the receiving side which concerns on this embodiment. It is a sequence diagram which shows the operation example of the communication system in the modification which concerns on this embodiment. It is a flowchart which shows the operation example of the communication device on the transmission side in the modification which concerns on this embodiment. It is a block diagram which shows an example of the schematic structure of a smartphone. It is a block diagram which shows an example of the schematic structure of a car navigation device. It is a block diagram which shows an example of the schematic structure of a wireless access point.

Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

The explanations will be given in the following order.
1. 1. Overview of communication system 2. Embodiments of the present disclosure 2-1. Outline of function 2-2. Functional configuration example 2-3. Information to be communicated 2-4. Operation example 3. Modification example 4. Application example 5. Summary

<1. Overview of communication system>
First, the configuration of the communication system according to the embodiment of the present disclosure will be described with reference to FIG. As shown in FIG. 1, the communication system according to the present disclosure is a wireless LAN system (for example, a wireless LAN system compliant with 802.11), and an AP (Access Point) 100, which is a base station of a communication device, and a child. It is composed of STA (Station) 200, which is a machine. In FIG. 1, the slave unit of AP100A is STA200A, and the slave unit of AP100B is STA200B.

The AP100A is a communication device that functions as a base station in a wireless LAN system. For example, the AP100A provides the STA200A with communication with the external network by being connected to the external network. For example, the AP100A is connected to the Internet and provides communication between the STA200A and a device on the Internet or a device connected via the Internet. The communication method, type, shape, etc. of the AP100A are not particularly limited. The AP100B has the same function as that of the AP100A described above, and the description thereof will be omitted in order to avoid duplicate explanations.

The STA200A is a communication device that functions as a slave unit in a wireless LAN system and communicates with the AP100A. For example, the STA200A is an arbitrary device such as a display having a display function, a memory having a storage function, a keyboard and a mouse having an input function, a speaker having a sound output function, and a smartphone having a function of executing advanced calculation processing. You may. The A communication method, type, shape, etc. of the STA200 are not particularly limited. The STA200B has the same function as that of the STA200B described above, and the description thereof will be omitted in order to avoid duplicate explanations.

In the specific description of the embodiment of the present disclosure, for example, the relationship between the data transmission / reception processing between the AP100A and the STA200A and the data transmission / reception processing between the AP100B and the STA200B will be described below.

<2. Embodiments of the present disclosure>
[2-1. Functional overview]
In the embodiment of the present disclosure, when a communication device transmits data to another communication device, it is determined whether or not to perform frame exchange based on the standard of IEEE802.11 and transmit data (data frame) based on the result. judge. Specifically, when transmitting a data frame to the STA 200, the AP 100 exchanges an RTS / CTS frame with the STA 200 and attempts to acquire the transmission right of the data frame. The AP100 determines whether or not to transmit the data frame to the STA 200 based on whether or not the data frame transmission right can be acquired by the RTS / CTS frame exchange.

Here, the RTS / CTS frame exchange is to exchange an RTS (Request to Send: transmission request) frame and a CTS (Clear to Send: transmission permission) frame between communication devices. By exchanging RTS / CTS frames, the communication devices can confirm the existence of each other, and data frames can be appropriately transmitted and received. In particular, RTS / CTS frame exchange is used as a countermeasure against the hidden terminal problem. The RTS frame is a frame including transmission request information (first frame), and the CTS frame is a frame including transmission permission information (second frame).

Further, in the embodiment of the present disclosure, the communication device uses channels having different frequency bands when exchanging frames and transmitting data. For example, the AP100 uses a channel having a frequency band of 5 GHz (first channel) as a control channel when exchanging RTS / CTS frames. Further, the AP100 uses a channel (second channel) having a frequency band of 6 GHz as a data channel when transmitting a data frame.

The use of the first channel and the second channel is not particularly limited. For example, the AP100 may use the first channel having a frequency band of 5 GHz as a data channel and the second channel having a frequency band of 6 GHz as a control channel.

Further, in the embodiment of the present disclosure, the band of the control channel having a frequency band of 5 GHz is a narrow band (for example, 20 MHz), and has a role as a channel for the communication device to exchange control information. Further, the band of the data channel having a frequency band of 6 GHz is a wide band (for example, 160 MHz), and has a role as a channel for the communication device to exchange data frames. However, the role of each channel described above is set in consideration of the utilization efficiency of the frequency band, and the role of each channel is not limited depending on the resource usage status. For example, when the usage status of the control channel is congested, the communication device may exchange control information on the data channel. The band of each channel is not particularly limited, and any band may be used for each channel.

The functional outline of the communication device according to the embodiment of the present disclosure has been described above. Subsequently, an example of the functional configuration of the communication device according to the embodiment of the present disclosure will be described.

[2-2. Function configuration example]
Hereinafter, an example of the functional configuration of the communication device according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram showing a functional configuration example of the communication device. In the following, the communication device refers to AP100, STA200, or one of them. Further, since each can have the same functional configuration, only the functional configuration of the AP100 will be described below, and the description of the functional configuration of the STA 200 will be omitted. Further, since this is only an example, the AP100 and the STA200 may have different functional configurations. For example, the AP100 may separately have a function of controlling a plurality of STAs 200.

As shown in FIG. 2, the AP100 includes a communication unit 110, an antenna 111, a data processing unit 130, a control unit 140, a storage unit 150, and a power supply unit 160.

(1) Communication unit 110
The communication unit 110 functions as a transmission unit and a reception unit, and has a function of transmitting and receiving an RTS frame, a CTS frame, and a data frame to another communication device. The communication unit 110 according to the embodiment of the present disclosure includes an amplifier unit 112, a wireless interface unit 114, a signal processing unit 116, a channel estimation unit 118, and a modulation / demodulation unit 120. When the amplifier unit 112 and the wireless interface unit 114 are combined as one set, the communication unit 110 may be provided with two or more sets (in the figure, a case where two or more sets are provided is shown as an example. There is). Further, the amplifier unit 112 may include its function in the wireless interface unit 114.

In the embodiment of the present disclosure, the AP 100 has at least two sets including the antenna 111, the amplifier unit 112 of the communication unit 110, and the wireless interface unit 114. Further, for example, one set of the antenna 111, the amplifier unit 112, and the wireless interface unit 114 is used in the control channel (first communication unit), and the other set is used in the data channel (second). Communication unit). The first communication unit is used for each communication device to transmit and receive an RTS frame and a CTS frame when the communication device exchanges RTS / CTS frames with another communication device. Further, the second communication unit is used for each communication device to transmit and receive a data frame when the communication device transmits and receives a data frame to and from another communication device.

Further, the communication unit 110 does not have to always operate both the first communication unit used in the control channel and the second communication unit used in the data channel, and the communication unit 110 may perform processing. Depending on the situation, only one of the first communication unit and the second communication unit may be operated. For example, the communication unit 110 may operate only the first communication unit when performing the RTS / CTS frame exchange processing, and may operate only the second communication unit when performing the data frame transmission / reception processing. Further, for example, the communication unit 110 of the communication device on the data frame transmission side keeps only the first communication unit in operation at all times, and when the CTS frame is received from the communication device on the data frame reception side, the second communication unit May be operated. Similarly, the communication unit 110 of the communication device on the data frame receiving side also keeps only the first communication unit in operation at all times, and when the CTS frame is transmitted to the communication device on the data frame transmitting side, the second communication unit is set. It may operate. As described above, the communication device can reduce the power consumption of the communication device by controlling the operation of the first communication unit and the second communication unit.

(Amplifier section 112)
The amplifier unit 112 performs signal amplification processing. More specifically, at the time of reception, the amplifier unit 112 amplifies the received signal input from the antenna 111 to a predetermined power and outputs it to the wireless interface unit 114 described later. At the time of transmission, the amplifier unit 112 amplifies the transmission signal input from the wireless interface unit 114 to a predetermined power and sends it to the antenna 111. Note that these functions may be realized by the wireless interface unit 114.

(Wireless interface unit 114)
At the time of reception, the wireless interface unit 114 acquires a baseband signal by down-converting the received signal, which is an analog signal provided by the amplifier unit 112, and filters and digitalizes the baseband signal. A received symbol stream is generated by performing various processes such as conversion to a signal, and is output to a signal processing unit 116 described later. Further, at the time of transmission, the wireless interface unit 114 converts the input from the signal processing unit 116 into an analog signal, performs filtering and up-conversion to the carrier frequency band, and sends the input to the amplifier unit 112.

(Signal processing unit 116)
At the time of reception, the signal processing unit 116 acquires an independent data symbol stream for each received symbol stream by performing spatial processing on the received symbol stream provided from the wireless interface unit 114, and the modulation / demodulation unit 120 described later. To provide to. Further, at the time of transmission, the signal processing unit 116 spatially processes the data symbol stream input from the modulation / demodulation unit 120, and provides one or more obtained transmission symbol streams to each wireless interface unit 114. ..

(Channel estimation unit 118)
The channel estimation unit 118 calculates the complex channel gain information of the propagation path from the preamble portion and the training signal portion of the received signals provided by each radio interface unit 114. The calculated complex channel gain information is used for demodulation processing in the modulation / demodulation unit 120 and spatial processing in the signal processing unit 116.

(Modification / demodulation unit 120)
At the time of reception, the modulation / demodulation unit 120 acquires received data by demodulating, deinterleaving, and decoding the data symbol stream provided by the signal processing unit 116, and provides the received data to the data processing unit 130. To do. Further, at the time of transmission, the modulation / demodulation unit 120 encodes, interleaves, and modulates the frame provided by the data processing unit 130 based on the coding and modulation method set by the control unit 140 described later. Generates a data symbol stream with, and provides the stream to the signal processing unit 116.

(2) Antenna 111
The antenna 111 has a single antenna element or a plurality of antenna elements, has a function of outputting a received signal from another communication device to the amplifier unit 112, and transmits a transmission signal input from the amplifier unit 112 to the other communication device. Has the function of

(3) Data processing unit 130
At the time of reception, the data processing unit 130 analyzes the MAC header for media access control (MAC: Media Access Control), detects errors in the frame, and the like for the received data provided by the modulation / demodulation unit 120. Has the function of performing. Further, at the time of transmission, the data processing unit 130 generates a packet (data) for transmission, and generates a frame for transmission by performing processing such as adding a MAC header and adding an error detection code to the packet. Then, the frame is provided to the modulation / demodulation unit 120.

Further, the data processing unit 130 provides the control unit 140 with information necessary for the determination process and the transmission control process in the control unit 140 among the received data. In addition, the data processing unit 130 also provides the RTS frame and the information regarding the data described in the CTS frame to the storage unit 150.

(4) Control unit 140
The control unit 140 has a function of controlling each of the above-mentioned configurations, and performs processing such as passing information between the above-mentioned components, setting parameters, and scheduling processing. For example, the control unit 140 sets parameters in the modulation / demodulation unit 120 and the signal processing unit 116, and schedules packets in the data processing unit 130. Further, for example, the control unit 140 performs parameter setting and transmission power control in the wireless interface unit 114 and the amplifier unit 112.

Further, in the present disclosure, the control unit 140 performs a determination process for controlling data communication, and controls whether or not to perform a data frame transmission / reception process based on the result of the determination process.

In order to realize the above-mentioned functions, the control unit 140 according to the embodiment of the present disclosure includes a determination unit 142 and a transmission control unit 144, as shown in FIG.

(Judgment unit 142)
The determination unit 142 has a function of performing a determination process for controlling data communication. Specifically, the determination unit 142 causes the communication unit 110 to transmit the data frame to the other communication device on the data channel based on the result of the communication unit 110 exchanging the RTS / CTS frame with another communication device on the control channel. Judge whether or not.

For example, the AP 100 transmits an RTS frame from the communication unit 110 to the STA 200 via a control channel. The determination unit 142 confirms whether or not the CTS frame has been received from the STA 200 by the time when a predetermined time (for example, the SIFS time) has elapsed. When the communication unit 110 receives the CTS frame before the SIFS time elapses, the determination unit 142 determines that data can be transmitted to the STA 200, and provides the determination result to the transmission control unit 144.

Here, the SIFS (Short Inter Frame Space) time is the shortest waiting time in the frame transmission interval. The predetermined time is not limited to SIFS, and an arbitrary time may be set.

If the communication unit 110 does not receive the CTS frame by the time the SIFS time elapses, the determination unit 142 determines that the data frame cannot be transmitted to the STA 200, and provides the determination result to the transmission control unit 144. .. Further, the determination unit 142 causes the communication unit 110 to perform the RTS frame transmission process until the determination result that the data frame can be transmitted to the STA 200 is obtained, and repeats the determination process each time.

In the above example, when the AP100 and the STA200 succeed in exchanging the RTS / CTS frame, the example in which the AP100 starts transmitting the data frame has been described, but the determination condition for the AP100 to start transmitting the data frame is described above. It is not limited to the example of. For example, the AP100 may start transmitting a data frame even if the CTS frame is not received by the time the SIFS time elapses after the RTS frame is transmitted. Further, the STA 200 may transmit a CTS frame describing the transmission start time of the data frame to the AP 100 and specify the transmission start time of the data frame even if the RTS frame is not received from the AP 100. Further, the frame used by the STA 200 to specify the transmission start time of the data frame is not limited to the RTS / CTS frame, and the STA 200 may specify the transmission start time of the data frame by a Tiger frame or the like.

(Transmission control unit 144)
The transmission control unit 144 has a function of controlling data communication. Specifically, the transmission control unit 144 has a function of controlling which channel each of the RTS frame, the CTS frame, and the data frame is transmitted. For example, in the embodiment of the present disclosure, the transmission control unit 144 causes the communication unit 110 to transmit the RTS frame and the CTS frame on the control channel and transmit the data frame on the data channel.

Further, the transmission control unit 144 also has a function of controlling whether or not to transmit the data frame to the communication unit 110 based on the determination result of the determination unit 142. For example, when the transmission control unit 144 obtains a determination result that the data frame is transmitted, the transmission control unit 144 causes the communication unit 110 to transmit the data frame on the data channel.

(5) Storage unit 150
The storage unit 150 has a function of storing information related to the data acquired by the data processing unit 130. When the processing of the control unit 140 requires information about the data, the storage unit 150 provides the information to the control unit 140 via the data processing unit.

(6) Power supply unit 160
The power supply unit 160 is composed of a battery power supply or a fixed power supply, and has a function of supplying electric power to a communication device.

[2-3. Information to be communicated]
Subsequently, an example of the information communicated by the AP100 and the STA200 will be described with reference to FIGS. 4 and 5.

In the embodiments of the present disclosure, the information communicated between the communication devices is an RTS frame, a CTS frame, and a data frame. The RTS frame is, for example, information transmitted by the AP100 to the STA200 on the control channel. The CTS frame is information transmitted by the STA 200 to the AP 100 via the control channel. The data frame is information transmitted by the AP 100 to the STA 200 on the data channel. Hereinafter, the configuration of each frame will be specifically described.

(1) RTS Frame An example of the RTS frame format will be described with reference to FIG. The configuration of a normal RTS frame is a configuration having, for example, "Frame Control", "Duration", "RA", "TA", and "FCS" fields among the fields shown in FIG.

In addition, the RTS frame of the embodiment of the present disclosure usually has a field of additional information about the data described in the data frame. Additional information is, for example, the "Format of Data", "BSS Color of Data", "Spatial Reason of Data", "Bandwidth of Data", and "Duration of Data" fields. The format of the frame is just an example. In the following, each field of the RTS frame will be described.

The Frame Control field has information on the frame type, transmission direction, frame attribute, and the like. Information indicating an RTS frame as a frame type corresponds to transmission request information. The Duration field contains information about how long the wireless line will be used. The RA field has information about the receiving station MAC address (RA: Receiver Address). The TA field has information about the transmitting station MAC address (TA: Transmitter Address).

The Format of Data field has Format information. The BSS Color of Data field has BSS identification information. The Spatial Reuse of Data field has spatial reuse information.

The Bandwidth of Data field has bandwidth information. The Duration of Data field has transmission time information. The FCS field is a field for performing frame error detection (FCS: Frame Check Sequence).

The additional information regarding the data can be described in the RTS frame to indicate the detailed information of the data to be transmitted by the communication device on the transmitting side to the communication device on the receiving side. In addition, the communication device on the receiving side can know additional information about the data in advance, and can reduce the overhead in the data frame in the data channel.

(2) CTS Frame Next, an example of the CTS frame format will be described with reference to FIG. The configuration of a normal CTS frame is a configuration having, for example, "Frame Control", "RA", and "FCS" fields among the information shown in FIG. In the embodiment of the present disclosure, the CTS frame additionally has, for example, "Transmit Start Time of Data" and "Duration of Data" fields as fields of information regarding the transmission start time and transmission end time of data. The format of the frame is just an example. In the following, each field of the CTS frame will be described.

The Frame Control field has information on the frame type, transmission direction, frame attribute, and the like. Information indicating a CTS frame as a frame type corresponds to transmission permission information. The RA field has information about the receiving station MAC address (RA: Receiver Address).

The Transmit Start Time of Data field contains information about the data transmission start time. The Duration of Data field contains information about the transmission time of the data. The FCS field is a field for performing frame error detection (FCS: Frame Check Sequence). The transmission end time can be calculated from the data transmission start time and the data transmission time.

(3) Data frame A data frame is a frame having data transmitted to and received from a communication device and additional information regarding the data. In the embodiments of the present disclosure, the additional information is not described in the data frame, but in the RTS frame. The specific fields of the additional information are the same as those described in (1) RTS frame, and the description thereof will be omitted in order to avoid duplicate explanations. Although the AP100 does not describe the additional information described in the RTS frame in the data frame, the AP100 describes the Training Field required for demodulation of the data frame received by the STA 200 in the data frame and transmits the data frame.

Further, the frame in which the additional information regarding the data is described is not limited to the RTS frame, and may be described in any frame. For example, additional information about the data may be described in the CTS frame. When the additional information regarding the data is described in the CTS frame, the receiving side communication device can instruct the transmitting side communication device to transmit the data described in the additional information.

As described above, an example of the information communicated by the AP100 and the STA200 according to the embodiment of the present disclosure has been described with reference to FIGS. Subsequently, an operation example of the communication system according to the embodiment of the present disclosure will be described.

[2-4. Operation example]
An operation example of the communication system according to the embodiment of the present disclosure will be described. Hereinafter, an operation example of the communication system will be described with reference to FIGS. 6 to 8.

(1) Operation Example of Communication System An operation example of the entire communication system according to the embodiment of the present disclosure will be described with reference to FIG. FIG. 6 is a sequence diagram showing an operation example of the communication system. In the embodiment of the present disclosure, the data frame transmission right acquisition process required for the determination process for controlling the data frame communication is performed only on the control channel. Further, it is assumed that the communication processing of the data frame is performed only on the data channel.

As shown in FIG. 6, firstly, AP100A after a back-off time lapses 300 transmits the RTS frame 308 in control channel STA200A (time _T 1). STA200A having received the RTS frame 308, AP100A, and transmits the CTS frame 312 in control channel STA200A (time _T 2).

At this time, since the AP100B uses the data channel for the transmission of the Data 304, the AP100A and the STA200A cannot use the data channel. Therefore, STA200A is, AP100B the information transmission completion time _{T 3} data frames in the data channel, and according to Transmit Start Time of Data field of the CTS frame as a transmission start time, transmits a CTS frame in the control channel. This transmission start time is information for AP100A, which is scheduled to transmit a data frame next.

In addition, the STA200A also describes the transmission time information of the data frame described in the Duration of Data field of the RTS frame received from the AP100A on the control channel in the Duration of Data field of the CTS frame. This transmission time information is information for the STA200B that may receive a data frame next to the STA200A. For example, it is assumed that the STA200B receives an RTS frame from the AP100B while the STA200A is receiving a data frame. The STA200B can describe the transmission time information described in the CTS frame previously received from the STA200A in the Duration of Data field of the CTS frame and transmit it to the AP100B.

After the AP100B completes the transmission of Data 304 on the data channel (time T ₃ ), the AP 100A starts transmitting Data 316 on the data channel to the STA 200A (time T ₃ ). After the transmission of Data 304 is completed and the backoff time 320 has elapsed, the AP100B transmits the RTS frame 324 on the control channel to the STA 200B in order to transmit the data frame again (time T ₄ ). The STA 200B that has received the RTS frame 324 on the control channel describes in the CTS frame 328 the same information as when the STA 200A transmits the CTS frame 312 on the control channel, and transmits the CTS frame 328 to the AP100B and the STA 200A on the control channel. (Time T ₅ ). Then, after the AP100A completes transmitting the Data 316 on the data channel (time T ₆ ), the AP 100B transmits the Data 332 to the STA 200B on the data channel (time T ₆ − time T ₇ ).

(2) Operation Example of Communication Device on the Data Frame Transmission Side Subsequently, a specific RTS / CTS frame exchange process in the communication device on the data frame transmission side will be described with reference to FIG. 7. In the following, for example, it is assumed that the communication device on the transmitting side is AP100 and the communication device on the receiving side is STA200. First, the AP100 transmits an RTS frame to the STA200A on the control channel before starting the data frame transmission process (step S1000). After transmitting the RTS frame, the AP100 confirms whether or not the CTS frame has been received on the control channel by the time the SIFS time elapses (step S1004). When the CTS frame is received (step S1004 / YES), the AP100 transmits the data frame to the STA 200 via the data channel at the transmission start time described in the received CTS frame (step S1008). If the CTS frame cannot be received (step S1004 / NO), the AP100 repeats the RTS frame transmission process and the determination process on the control channel until the CTS frame can be received.

(3) Operation Example of Communication Device on the Data Frame Receiving Side Subsequently, a specific RTS / CTS frame exchange process in the communication device on the data frame reception side will be described with reference to FIG. In the following, for example, as in the description of FIG. 7, the communication device on the receiving side is STA200, and the communication device on the transmitting side is AP100. First, the STA 200 receives the RTS frame on the control channel (step S1100). The STA 200 holds additional information regarding the data described in the received RTS frame in the storage unit 150 (step S1104). The STA 200 confirms whether a data frame reserved for transmission exists in the data channel (step S1108). The STA 200 determines the time at which all the data frames reserved for transmission complete the transmission as the transmission start time of the data frames (step S1112). After determining the transmission start time, the STA 200 describes the transmission start time, which is the time when the AP100 starts transmitting the data frame on the data channel, in the CTS frame (step S1116), and transmits the CTS frame to the AP100 on the control channel (step S1116). Step S1120).

The embodiment of the present disclosure has been described above with reference to FIGS. 2 to 8. Subsequently, a modified example according to the embodiment of the present disclosure will be described.

<3. Modification example>
Hereinafter, a modified example of one embodiment of the present disclosure will be described. The modifications described below may be applied alone to the embodiments of the present disclosure, or may be applied in combination to the embodiments of the present disclosure. Further, the modified example may be applied in place of the configuration described in the embodiment of the present disclosure, or may be additionally applied to the configuration described in the embodiment of the present disclosure.

In the embodiment of the present disclosure, an example has been described in which the data frame transmission right acquisition process is performed on the control channel. However, the process of acquiring the transmission right of the data frame may be performed on the data channel by a method different from the method performed on the control channel. For example, the AP100 confirms the usage status of the data channel and the control channel before starting the transmission of the data frame. The AP100 may select a channel to be used according to the usage status of each channel, and perform a data frame transmission right acquisition process by a method according to the selected channel. Hereinafter, specific processing examples will be described with reference to FIGS. 9 and 10.

(1) Operation Example of Communication System in Modified Example First, an example of a specific operation in the communication system in the modified example will be described with reference to FIG. First, the AP100A confirms the usage status of the data channel and the control channel before transmitting the data frame to the STA200A. As a result of the confirmation, the data channel is a non-use state, AP100A may try to acquire the transmission right of the data frame by the back-off control 400 on the data channel (time T _11). When the AP100A can acquire the transmission right of the data frame by the backoff control 400, the AP100A transmits the Data 404 to the STA 200A via the data channel (time T _{12 to} time T ₁₅ ). When the transmission right is acquired in the data channel, the AP100 and the STA200A do not exchange RTS / CTS frames, so that the AP100 does not transmit additional information to the STA200A. Therefore, the AP100 may describe additional information in the data frame.

While the AP100A is transmitting a data frame on the data channel, the AP100B checks the usage status of the data channel and the control channel before starting the transmission of the data frame, even if the AP100B attempts to transmit the data frame. As a result of confirmation, it was found that the data channel of AP100B is used by another communication device. At the same time, AP100B the control channel for has also been found that an unused state, after a back-off time 408 has elapsed, transmits an RTS frame 412 in the control channel to the STA 200b (time _T 13). The STA 200B transmits the CTS frame 416 to the AP 100B via the control channel based on the information described in the received RTS frame 412 (time T ₁₄ ). Based on the information described in the received CTS frame 416, the AP100B transmits the Data 420 to the STA200B on the data channel (time T ₁₅ -time T ₁₆ ) after the AP 100A completes the transmission of the Data 404 on the data channel (time T ₁₅ ). ).

(2) Operation Example of Communication Device on the Data Frame Transmitting Side in the Modified Example Next, a specific data transmission process on the communication device on the data frame transmitting side in the modified example will be described with reference to FIG. In the following, it is assumed that the communication device on the transmitting side is, for example, AP100. First, the AP100 confirms the usage status of the data channel and the control channel before starting the data frame transmission process (step S2000). When the data channel is unused (step S2004 / YES), the AP100 acquires the transmission right of the data frame by the backoff control in the data channel (step S2008). After acquiring the right to transmit the data frame, the AP100 transmits the data frame on the data channel (step S2012).

When the data channel is in use (step S2004 / NO), the AP100 confirms the usage status of the control channel (step S2016). If the control channel is unused (step S2016 / YES), the AP100 transmits an RTS frame on the control channel (step S2020). When the AP100 receives the CTS frame on the control channel from the time when the RTS frame is transmitted to the time when the SIFS time elapses (step S2024 / YES), the AP100 transmits the data frame. Specifically, the AP100 transmits a data frame on the data channel at the transmission start time described in the received CTS frame (step S2028). If the AP100 does not receive the CTS frame on the control channel after the RTS frame is transmitted until the SIFS time elapses (step S2024 / NO), the AP100 transmits the RTS frame again on the control channel (step S2020). ).

If the control channel is also in use (step S2016 / NO), the AP100 waits until either the data channel or the control channel is in an unused state (step S2032).

(3) Operation example of the communication device on the data frame receiving side in the modified example The operation example of the communication device on the data frame transmitting side in the modified example is the same as the operation example of the communication device on the data frame transmitting side in the embodiment of the present disclosure. Yes, the explanation is omitted to avoid duplicate explanation.

As described above, a modified example according to the embodiment of the present disclosure has been described with reference to FIGS. 9 and 10. Subsequently, an application example of the technique according to the embodiment of the present disclosure will be described.

<4. Application example>
The technology according to the present disclosure can be applied to various products. For example, the STA200 is a smartphone, a tablet PC (Personal Computer), a notebook PC, a mobile terminal such as a portable game terminal or a digital camera, a fixed terminal such as a television receiver, a printer, a digital scanner or a network storage, or a car navigation device. It may be realized as an in-vehicle terminal such as. Further, the STA200 is realized as a terminal (also referred to as an MTC (Machine Type Communication) terminal) that performs M2M (Machine To Machine) communication such as a smart meter, a vending machine, a remote monitoring device, or a POS (Point Of Sale) terminal. You may. Further, the STA 200 may be a wireless communication module (for example, an integrated circuit module composed of one die) mounted on these terminals.

On the other hand, for example, the AP100 may be realized as a wireless LAN access point (also referred to as a wireless base station) having a router function or not having a router function. Further, the AP100 may be realized as a mobile wireless LAN router. Further, the AP100 may be a wireless communication module (for example, an integrated circuit module composed of one die) mounted on these devices.

[4-1. First application example]
FIG. 11 is a block diagram showing an example of a schematic configuration of a smartphone 900 to which the technology according to the present disclosure can be applied. The smartphone 900 includes a processor 901, a memory 902, a storage 903, an external connection interface 904, a camera 906, a sensor 907, a microphone 908, an input device 909, a display device 910, a speaker 911, a wireless communication interface 913, an antenna switch 914, and an antenna 915. It includes a bus 917, a battery 918 and an auxiliary controller 919.

The processor 901 may be, for example, a CPU (Central Processing Unit) or a System (System on Chip), and controls the functions of the application layer and other layers of the smartphone 900. The memory 902 includes a RAM (Random Access Memory) and a ROM (Read Only Memory), and stores programs and data executed by the processor 901. The storage 903 may include a storage medium such as a semiconductor memory or a hard disk. The external connection interface 904 is an interface for connecting an external device such as a memory card or a USB (Universal Serial Bus) device to the smartphone 900.

The camera 906 has an image pickup device such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and generates an image pickup image. The sensor 907 may include, for example, a group of sensors such as a positioning sensor, a gyro sensor, a geomagnetic sensor and an acceleration sensor. The microphone 908 converts the voice input to the smartphone 900 into a voice signal. The input device 909 includes, for example, a touch sensor, a keypad, a keyboard, a button, or a switch for detecting a touch on the screen of the display device 910, and receives an operation or information input from the user. The display device 910 has a screen such as a liquid crystal display (LCD) or an organic light emitting diode (OLED) display, and displays an output image of the smartphone 900. The speaker 911 converts the voice signal output from the smartphone 900 into voice.

The wireless communication interface 913 supports one or more of the wireless LAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac and 11ad to perform wireless communication. The wireless communication interface 913 may communicate with other devices via the wireless LAN access point in the infrastructure mode. In addition, the wireless communication interface 913 can directly communicate with other devices in an ad hoc mode or a direct communication mode such as Wi-Fi Direct (registered trademark). In Wi-Fi Direct, unlike the ad hoc mode, one of the two terminals operates as an access point, but communication is directly performed between the terminals. The wireless communication interface 913 can typically include a baseband processor, an RF (Radio Frequency) circuit, a power amplifier, and the like. The wireless communication interface 913 may be a one-chip module in which a memory for storing a communication control program, a processor for executing the program, and related circuits are integrated. In addition to the wireless LAN system, the wireless communication interface 913 may support other types of wireless communication systems such as a short-range wireless communication system, a proximity wireless communication system, or a cellular communication system. The antenna switch 914 switches the connection destination of the antenna 915 between a plurality of circuits (for example, circuits for different wireless communication methods) included in the wireless communication interface 913. The antenna 915 has a single antenna element or a plurality of antenna elements (for example, a plurality of antenna elements constituting a MIMO antenna), and is used for transmitting and receiving a radio signal by the radio communication interface 913.

Not limited to the example of FIG. 11, the smartphone 900 may be provided with a plurality of antennas (for example, an antenna for a wireless LAN and an antenna for a proximity wireless communication method). In that case, the antenna switch 914 may be omitted from the configuration of the smartphone 900.

The bus 917 connects the processor 901, the memory 902, the storage 903, the external connection interface 904, the camera 906, the sensor 907, the microphone 908, the input device 909, the display device 910, the speaker 911, the wireless communication interface 913, and the auxiliary controller 919 to each other. .. The battery 918 supplies electric power to each block of the smartphone 900 shown in FIG. 11 via a power supply line partially shown by a broken line in the figure. The auxiliary controller 919 operates the minimum necessary functions of the smartphone 900, for example, in the sleep mode.

The smartphone 900 may operate as a wireless access point (software AP) by the processor 901 executing the access point function at the application level. Further, the wireless communication interface 913 may have a wireless access point function.

[4-2. Second application example]
FIG. 12 is a block diagram showing an example of a schematic configuration of a car navigation device 920 to which the technique according to the present disclosure can be applied. The car navigation device 920 includes a processor 921, a memory 922, a GPS (Global Positioning System) module 924, a sensor 925, a data interface 926, a content player 927, a storage medium interface 928, an input device 929, a display device 930, a speaker 931, and wireless communication. It includes an interface 933, an antenna switch 934, an antenna 935 and a battery 938.

The processor 921 may be, for example, a CPU or SoC, and controls the navigation function and other functions of the car navigation device 920. Memory 922 includes RAM and ROM and stores programs and data executed by processor 921.

The GPS module 924 uses GPS signals received from GPS satellites to measure the position (eg, latitude, longitude and altitude) of the car navigation device 920. The sensor 925 may include, for example, a group of sensors such as a gyro sensor, a geomagnetic sensor and a barometric pressure sensor. The data interface 926 is connected to the vehicle-mounted network 941 via a terminal (not shown), and acquires data generated on the vehicle side such as vehicle speed data.

The content player 927 reproduces the content stored in the storage medium (for example, a CD or DVD) inserted into the storage medium interface 928. The input device 929 includes, for example, a touch sensor, a button, or a switch that detects a touch on the screen of the display device 930, and accepts an operation or information input from the user. The display device 930 has a screen such as an LCD or an OLED display, and displays an image of a navigation function or a content to be reproduced. The speaker 931 outputs the sound of the navigation function or the content to be played.

The wireless communication interface 933 supports one or more of the wireless LAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac and 11ad to perform wireless communication. The wireless communication interface 933 may communicate with other devices via the wireless LAN access point in the infrastructure mode. Further, the wireless communication interface 933 can directly communicate with other devices in an ad hoc mode or a direct communication mode such as Wi-Fi Direct. The wireless communication interface 933 may typically include a baseband processor, an RF circuit, a power amplifier, and the like. The wireless communication interface 933 may be a one-chip module in which a memory for storing a communication control program, a processor for executing the program, and related circuits are integrated. In addition to the wireless LAN system, the wireless communication interface 933 may support other types of wireless communication systems such as a short-range wireless communication system, a proximity wireless communication system, or a cellular communication system. The antenna switch 934 switches the connection destination of the antenna 935 between a plurality of circuits included in the wireless communication interface 933. The antenna 935 has a single or multiple antenna elements and is used for transmitting and receiving radio signals by the wireless communication interface 933.

Not limited to the example of FIG. 12, the car navigation device 920 may include a plurality of antennas. In that case, the antenna switch 934 may be omitted from the configuration of the car navigation device 920.

The battery 938 supplies electric power to each block of the car navigation device 920 shown in FIG. 12 via a power supply line partially shown by a broken line in the figure. In addition, the battery 938 stores electric power supplied from the vehicle side.

Further, the wireless communication interface 933 may operate as the AP100 described above and provide a wireless connection to a terminal owned by a user in a vehicle.

Further, the technique according to the present disclosure may be realized as an in-vehicle system (or vehicle) 940 including one or more blocks of the car navigation device 920 described above, an in-vehicle network 941, and a vehicle-side module 942. The vehicle-side module 942 generates vehicle-side data such as vehicle speed, engine speed, or failure information, and outputs the generated data to the vehicle-mounted network 941.

[4-3. Third application example]
FIG. 13 is a block diagram showing an example of a schematic configuration of a wireless access point 950 to which the technique according to the present disclosure can be applied. The wireless access point 950 includes a controller 951, a memory 952, an input device 954, a display device 955, a network interface 957, a wireless communication interface 963, an antenna switch 964, and an antenna 965.

The controller 951 may be, for example, a CPU or a DSP (Digital Signal Processor), and has various functions (for example, access restriction, routing, encryption, firewall) of the IP (Internet Protocol) layer of the wireless access point 950 and higher layers. And log management, etc.) are operated. The memory 952 includes a RAM and a ROM, and stores a program executed by the controller 951 and various control data (for example, a terminal list, a routing table, an encryption key, a security setting, and a log).

The input device 954 includes, for example, a button or a switch, and receives an operation from the user. The display device 955 includes an LED lamp and the like, and displays the operation status of the wireless access point 950.

The network interface 957 is a wired communication interface for the wireless access point 950 to connect to the wired communication network 958. The network interface 957 may have a plurality of connection terminals. The wired communication network 958 may be a LAN such as Ethernet (registered trademark) or a WAN (Wide Area Network).

The wireless communication interface 963 supports one or more of the wireless LAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac and 11ad, and provides a wireless connection as an access point to nearby terminals. The wireless communication interface 963 may typically include a baseband processor, an RF circuit, a power amplifier, and the like. The wireless communication interface 963 may be a one-chip module in which a memory for storing a communication control program, a processor for executing the program, and related circuits are integrated. The antenna switch 964 switches the connection destination of the antenna 965 among a plurality of circuits included in the wireless communication interface 963. Antenna 965 has a single or multiple antenna elements and is used for transmission and reception of radio signals by the radio communication interface 963.

<5. Summary>
From the above description, the communication device according to the present disclosure can perform RTS / CTS frame exchange using the control channel, and perform data frame communication processing on a data channel having a frequency band different from that of the control channel. .. From the above, it is possible to provide a new and improved communication device, program and communication method capable of performing wireless communication more efficiently.

Although the preferred embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that anyone with ordinary knowledge in the technical field of the present disclosure may come up with various modifications or modifications within the scope of the technical ideas set forth in the claims. Of course, it is understood that it belongs to the technical scope of the present disclosure.

In addition, the series of processes by each device described in the present specification may be realized by using software, hardware, or a combination of software and hardware. The programs constituting the software are stored in advance in, for example, a recording medium (non-temporary medium: non-transitory media) provided inside or outside each device. Then, each program is read into RAM at the time of execution by a computer and executed by a processor such as a CPU.

In addition, the processes described in the present specification using the flowchart and the sequence diagram do not necessarily have to be executed in the order shown. Some processing steps may be performed in parallel. Further, additional processing steps may be adopted, and some processing steps may be omitted.

In addition, the effects described herein are merely explanatory or exemplary and are not limited. That is, the techniques according to the present disclosure may exhibit other effects apparent to those skilled in the art from the description herein, in addition to or in place of the above effects.

The following configurations also belong to the technical scope of the present disclosure.
(1)
A first communication unit that uses the first channel to exchange frames with other communication devices based on the IEEE802.11 standard.
A second communication unit that communicates a data frame with the other communication device by using a second channel having a frequency band different from that of the first channel.
Based on the result of the frame exchange, the control unit that controls the communication of the data frame and
A communication device.
(2)
The first communication unit transmits and receives a first frame, which is a frame containing transmission request information, and a second frame, which is a frame containing transmission permission information, to and from the other communication device, according to (1). The communication device described.
(3)
The communication device according to (2) above, wherein the first frame includes additional information regarding the data frame.
(4)
The additional information is information contained in at least one of a Format of Data field, a BSS Color of Data field, a Spatial Reason of Data field, a Bandwidth of Data field, and a Duration of Data field in (3). The communication device described.
(5)
The communication device according to (2) above, wherein the second frame includes a transmission start time when the data frame is transmitted from the second communication unit to the other communication device.
(6)
When the control unit determines that the data frame can be transmitted to the other communication device based on the result of the frame exchange in the first communication unit, the control unit transmits the data frame to the second communication unit. The communication device according to any one of (1) to (5) above, which is transmitted to a communication device.
(7)
When the control unit receives the second frame from the other communication device within a predetermined time after the first communication unit transmits the first frame to the other communication device, the control unit receives the second frame. The communication device according to (6) above, wherein the communication unit of the above (6) transmits the data frame to the other communication device.
(8)
When the first communication unit receives the first frame from another communication device, the control unit determines a transmission start time, and transmits a second frame including the transmission start time to the other communication device. The communication device according to (6) above, which is transmitted to the first communication unit.
(9)
The second communication unit receives the data frame transmitted from the other communication device, and transmits the data frame to the other communication device based on the instruction of the control unit. The communication device according to any one of (8).
(10)
The communication device according to (9) above, wherein the second communication unit transmits the data frame that does not include additional information.
(11)
The communication device according to any one of (1) to (10) above, wherein the first communication unit exchanges frames with other communication devices by RTS / CTS frame exchange.
(12)
Computer,
A first communication unit that uses the first channel to exchange frames with other communication devices based on the IEEE802.11 standard.
A second communication unit that communicates a data frame with the other communication device by using a second channel having a frequency band different from that of the first channel.
Based on the result of the frame exchange, the control unit that controls the communication of the data frame and
A program to function as.
(13)
Using the first channel, frame exchange based on the IEEE802.11 standard with other communication devices, and
Using the second channel, which has a frequency band different from that of the first channel, to communicate the data frame with the other communication device,
Controlling the communication of the data frame based on the result of the frame exchange
Communication methods performed by the processor, including.

100 AP
110 Communication unit 111 Antenna 112 Amplifier unit 114 Wireless interface unit 116 Signal processing unit 118 Channel estimation unit 120 Modulation / demodulation unit 130 Data processing unit 140 Control unit 142 Judgment unit 144 Transmission control unit 150 Storage unit 160 Power supply unit 200 STA

Claims (13)

A first communication unit that uses the first channel to exchange frames with other communication devices based on the IEEE802.11 standard.
A second communication unit that communicates a data frame with the other communication device by using a second channel having a frequency band different from that of the first channel.
Based on the result of the frame exchange, the control unit that controls the communication of the data frame and
A communication device. The first aspect of claim 1, wherein the first communication unit transmits and receives a first frame including transmission request information and a second frame including transmission permission information to and from the other communication device. Communication device. The communication device according to claim 2, wherein the first frame includes additional information regarding the data frame. The additional information is the information contained in at least one of the Format of Data field, the BSS Color of Data field, the Spatial Reason of Data field, the Bandwidth of Data field, and the Duration of Data field, according to claim 3. Communication device. The communication device according to claim 2, wherein the second frame includes a transmission start time when the data frame is transmitted from the second communication unit to the other communication device. When the control unit determines that the data frame can be transmitted to the other communication device based on the result of the frame exchange in the first communication unit, the control unit transmits the data frame to the second communication unit. The communication device according to claim 1, which is transmitted to the communication device. When the first communication unit transmits the first frame to the other communication device and then receives the second frame from the other communication device within a predetermined time, the control unit receives the second frame from the other communication device. The communication device according to claim 6, wherein the communication unit of the above 6 transmits the data frame to the other communication device. When the first communication unit receives the first frame from another communication device, the control unit determines a transmission start time, and transmits a second frame including the transmission start time to the other communication device. The communication device according to claim 6, wherein the communication device is transmitted to the first communication unit. The first aspect of claim 1, wherein the second communication unit receives the data frame transmitted from the other communication device and transmits the data frame to the other communication device based on an instruction of the control unit. Communication device. The communication device according to claim 9, wherein the second communication unit transmits the data frame that does not include additional information. The communication device according to claim 1, wherein the first communication unit exchanges frames with another communication device by exchanging RTS / CTS frames. Computer,
A first communication unit that uses the first channel to exchange frames with other communication devices based on the IEEE802.11 standard.
A second communication unit that communicates a data frame with the other communication device by using a second channel having a frequency band different from that of the first channel.
Based on the result of the frame exchange, the control unit that controls the communication of the data frame and
A program to function as. Using the first channel, frame exchange based on the IEEE802.11 standard with other communication devices, and
Using the second channel, which has a frequency band different from that of the first channel, to communicate the data frame with the other communication device,
Controlling the communication of the data frame based on the result of the frame exchange
Communication methods performed by the processor, including.

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